The present invention relates to valve plate assembly positioning structures for compressors.
Japanese Unexamined Utility Model Publication No. 55-156282 and Japanese Unexamined Patent Publication No. 10-231783 describe typical valve plate assembly positioning structures for compressors. These structures includes projections, or dowels. Specifically, as shown in FIGS. 6 and 7, a piston type compressor of Japanese Unexamined Utility Model Publication No. 55-156282 includes a cylinder block 51 and a housing section 52. A valve plate assembly 53 is arranged between the cylinder block 51 and the housing section 52. The valve plate assembly 53 includes a first section 54, a main section 55, a second section 56, and a third section 57.
A plurality of cylinder bores 58 are formed in the cylinder block 51. Each cylinder bore 58 accommodates a piston 59. The pistons 59 move in the associated cylinder bores 58. The main section 55 has suction ports 55a and discharge ports 55b. The first section 54 includes a plurality of suction valves 54a. Each suction valve 54a is located at a position corresponding to the associated suction port 55a. The second section 56 includes a plurality of discharge valves 56a. Each discharge valve 56a is located at a position corresponding to the associated, discharge port 55b. 
The main section 55 has a plurality of (in this case, two) projections 60. The projections 60 are formed in the main section 55 by pressing. As shown in FIG. 7, the second section 56 has a plurality of (in this case, two) holes 61 at positions corresponding to the projections 60. A discharge chamber 62 and a suction chamber 63 are defined in the housing section 52. The suction chamber 63 surrounds the discharge chamber 62. A partition 52a separates the discharge chamber 62 from the suction chamber 63.
As shown in FIG. 6, the first section 54, the main section 55, and the third section 57 are secured to an outer wall 64 of the rear housing section 52 and an outer wall of the cylinder block 51 by a plurality of pins 66. The second section 56 is positioned relative to the main section 55 by engagement of the projections 60 with the associated holes 61.
Normally, the second section 56 of the valve plate assembly 53 is sized to fit in the discharge chamber 62. As described above, a positioning structure for the second section 56 includes the projections 60.
However, if the valve plate assembly positioning structure employs the projections 60, the projections 60 must be formed on the main section 55 with a press. This step complicates the manufacturing procedure of the main section 55. Furthermore, since the length of the projections 60 is relatively small, the compressor may be assembled without fitting the projections 60 of the main section 55 securely in the associated holes 61 of the second section 56. The second section 56 may thus deviate from the proper position relative to the main section 55. To avoid this problem, the length of the projections 60 may be increased such that the projections 60 are more reliably fitted in the associated holes 61. This measure would prevent the second section 56 from deviating from the proper position relative to the main section 55. However, if the length of the projections 60 is increased, the accuracy of forming the projections 60 is decreased, thus reducing the positioning accuracy of the second section 56.
Furthermore, the projections 60 may be replaced by pins. However, this increases the number of parts used for positioning the valve plate assembly 53, thus complicating the positioning structure as a whole.
Accordingly, it is an objective of the present invention to provide a simplified valve plate assembly positioning structure for compressors.
To achieve the above objective, the present invention provides a compressor. The compressor comprises a cylinder block having a cylinder bore. A housing element has a suction chamber and a discharge chamber. A valve plate assembly is located between the cylinder block and the housing element to separate the cylinder bore from the suction chamber and the discharge chamber. The valve plate assembly includes a plurality of plate elements. The housing element is connected with cylinder block through the valve plate assembly. A positioning member engages all the plate elements to determine the position of the valve plate assembly relative to at least one of the cylinder block and the housing element.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.